Functional film and method of pattern formation

ABSTRACT

A pattern forming method for forming a functional film with a prescribed pattern on a substrate using a droplet discharge method, the pattern forming method includes: a sub region configuration process for: configuring, in a design pattern of the functional film, a plurality of sub regions which divide the designing pattern; and categorizing the plurality of sub regions into a plurality of non-adjacent groups; a first drawing process for arranging the liquid substance so as to draw a sub region that belongs to a first group categorized in the sub region configuration process; and a second drawing process for arranging the liquid substance so as to draw a sub region that belongs to a second group categorized in the sub region configuration process; wherein a solidification process for solidifying the liquid substance arranged in the first drawing process is provided between the first drawing process and the second drawing process.

BACKGROUND

1. Technical Field

The present invention relates to a functional film formed using adroplet discharge method, and the method for forming a pattern of thefunctional film using the droplet discharge method.

2. Related Art

In recent years, a technique, using the droplet discharge method as amethod for formation of fine wiring patterns, such as those used insemiconductor integrated circuits, has been disclosed. JapaneseUnexamined Patent Publication No. 2003-317945 is an example of therelated art. In the technology disclosed in this literature, a liquidsubstance, which includes a functional material (a conductive materialfor instance), is discharged from a droplet discharge head to asubstrate, and arranges the material on the substrate, thereby forming awiring pattern, and is considered to be very effective in handlingsmall-batch multi-product manufacturing.

Since the wiring (functional film) pattern formed with the above methodis of an extremely fine structure, the liquid substance arranged on thesubstrate endows with a great kinetic effect of the surface/interface(for example, surface tension or wetness). Setting aside the case wherethe liquid substance is arranged on the substrate in an independentdroplet, in the case where a multiple droplets are overlapping on thesubstrate and the liquid substance is forming an aggregation of givenpatterns, the liquid substance pattern may be deformed or may be splitby this kinetic effect. In other words, it may be difficult to form theliquid substance pattern according to the design pattern of thesubstrate.

SUMMARY

The advantage of the invention is to provide a functional film and amethod for forming a pattern that allows the formation of the functionalfilm pattern with a high precision of line width and of shape, etc.

According to an aspect of the invention, a pattern forming method forforming a functional film with a prescribed pattern on a substrate usinga droplet discharge method, the pattern forming method includes: a subregion configuration process for: configuring, in a design pattern ofthe functional film, a plurality of sub regions which divide thedesigning pattern; and categorizing the plurality of sub regions into aplurality of non-adjacent groups; a first drawing process for arrangingthe liquid substance so as to draw a sub region that belongs to a firstgroup categorized in the sub region configuration process; and a seconddrawing process for arranging the liquid substance so as to draw a subregion that belongs to a second group categorized in the sub regionconfiguration process; wherein a solidification process for solidifyingthe liquid substance arranged in the first drawing process is providedbetween the first drawing process and the second drawing process.

Here, the functional film indicates a membranous substance that exhibitsa prescribed function, and includes a luminescence film, a coloringfilm, and a conductive film, etc. The main functions of these functionalfilms are luminance, absorptivity, and conductivity. The functionalmaterial that has such main functions may include, for instance, anorganic electro luminescence (EL) material as a luminescence material,pigments as an absorptive material, and a metal as a conductivematerial.

The design pattern indicates a motif pattern of the functional film tobe formed, and is represented this way in order to distinguish itselffrom the actual pattern formed with the liquid substance or filmmaterial.

As mentioned above, in the case where the liquid substance is forming anaggregation of given patterns, the liquid substance pattern may bedeformed or split as a result of wetting or surface tension. Thebehavior of such liquid substance largely depends on the sizes andshapes of the liquid substance pattern that is arranged on thesubstrate.

With the method for forming a pattern according to the above aspect ofthe invention, a pattern of functional film is formed per group ofnon-adjacent sub regions, thereby allowing the behavior control of theliquid substance arranged on the substrate, by the shapes and sizes ofthe configured sub regions. Hence, the pattern can be formed in a highprecision of line width and of shape, etc.

In this case, in the pattern forming method, the solidification processmay dry the liquid substance arranged in the first drawing process.

In a drawing process that performs drying, the functional film isobtained by fixing a solid content contained in the liquid substance,performed by drying it. Here, a highly larger quantity, in comparison tothe volume of the obtained functional film, of the liquid substance isrequired when drawing in accordance with the design pattern, the size ofwhich significantly effects the behavior of the liquid substance and theshapes of the patterns. In the above aspect of the invention, since theliquid substance pattern is solidified per sub regional group, it ispossible to obtain the functional film in a high precision with thepattern forming method using the drying process.

The solidification process can be conducted, for instance, by radiatingultraviolet rays on the liquid substance that includes a lightcoagulated resin as the liquid substance. However, in that case, thepossible composition of the liquid substance is limited. In this methodfor forming the pattern, the liquid substance pattern, formed in thefirst drawing process, is solidified by drying it, thereby broadeningthe choice for liquid substances.

In this case, in the pattern forming method, the sub regionconfiguration process may configure the sub region to have a shape whichis possible to regulate so that it has an approximate constant width.

Here, the constant, possible-to-regulate shape indicates a shape thatcan be objectively regulated to have a constant width, such as arectangular shape, or a shape such as a quadrate, in which the width andthe length cannot be distinguished. Moreover, circular or ellipticalshapes also fall under that category, considering their diameter or thelength of their minor axis as a width. Further, among trapezoids, wherethe width may change, particularly those having a small amount of changein their width, may also fall under that category.

In the case where the liquid substance is arranged on the substrate in aspecific design pattern, the behavior of the liquid substance isstrongly influenced by the width of the design pattern. For example, ifthe liquid substance is arranged in the design pattern where a wideregion and a narrow region are merged, the liquid substance flows fromthe narrow region to the wide region, because of the difference of thecurvature (which depends on the width) at the liquid substance surface,resulting in a thickness difference between the two regions.Consequently, if the liquid substance pattern is formed while containingthe regions in which the widths significantly differ, the behavior ofthe liquid substance cannot be controlled well.

With the pattern forming process according to the above aspect of theinvention, the above problem can be avoided by making the sub regionshave shapes with constant widths.

In this case, in the pattern forming method, the sub regionconfiguration process may conduct a division of the sub region or acategorization of a group, so that the sub regions, which are regulatedto have comparable widths, belong to the same group.

The widths of the sub regions have a great effect on the behavior of theliquid substance, in case the liquid substance pattern that correspondsto the sub regions is formed. Hence, the liquid substance can beappropriately controlled, by making the sub regions having similarwidths belong to the same group.

In this case, in the pattern forming method, the design pattern of thefunctional film may include a long, thin, extended region; the subregion may be configured, along the direction in which the extendedregion extends, so as to segment the extended region at a certainprescribed length or less; and the prescribed length may be equal to oneinterval between protruding portions which emerge in approximately evenintervals in a liquid substance pattern, formed if the second liquidsubstance is arranged at once so as to draw a strap-like pattern withthe same width as the extended region.

Here, the extended long and thin regions do not necessarily indicateonly a rectilinear shape, and may also indicate a bended belt-shape.

In the case of arranging the liquid substance in the design pattern thatis extended long and thin, protruding portions (bulges) of liquidhuddling may be formed in the liquid substance pattern, as a result ofthe behavior of the liquid substance after its discharge. According tothe knowledge of the inventor, the protruding portions are thought toemerge as a result of the liquid substance arranged in a region with anarrow width, which causes the liquid substance to reduce the increasedinternal pressure.

According to this pattern formation method, in the case where the designpattern of the functional film includes a region extended long and thin,it is possible to form the liquid substance pattern in a high precisionwithout the emerging of the aforementioned protruding portions, byconfiguring the sub regions while segmenting the pattern to regionssmaller than the occurrence interval of the protruding portions.

In this case, in the pattern forming method, the design pattern of thefunctional film may include a long, thin, extended region; and the subregion may be configured, along the direction in which the extendedregion extends, so as to segment the extended region at a certainprescribed length or less; the pattern forming method may furtherinclude: a dummy pattern forming process which is performed prior to thesub region configuration process, and in which the second liquidsubstance is arranged on a dummy substrate so as to draw the strap-likepattern with the same width as the extended region, thereby forming adummy pattern; wherein the prescribed length may be regulated by theintervals between the protruding portions which emerge in approximatelyeven intervals in the dummy pattern.

The intervals of the aforementioned protruding portions depend on thewetness between the liquid substance and the substrate surface, thesurface tension of the liquid substance, the width of the designpattern, and the quantity of the arranged liquid substance; they changeaccording to the kind of the functional film to be formed. According tothis pattern forming method, it is possible to know the occurrenceinterval of the protruding portions, by forming, in advance, the dummypattern on the dummy substrate, on which the processing is performedwith the same conditions (the quality of material, the method of surfaceprocessing, the composition of the liquid substance, or the like) asthat of the functional films to be formed.

In this case, in the pattern forming method, a liquid-repellentprocessing or a bank formation may be performed on a surface, on whichthe pattern of the substrate is formed, in a manner that surrounds aregion corresponding to the design pattern of the functional film.

In this pattern forming method, it is possible to securely keep theliquid substance that is arranged on the substrate within the subregions, using the liquid-repellent processing and the bank formation.

According to another aspect of the invention, a functional film formedin a prescribed pattern is formed so that it is divided into a pluralityof sub regions.

The functional film, according to the above aspect of the invention, isformed by a sub region unit, excelling in the precision of filmthickness and the shape of the pattern.

In this case, in the functional film, the sub region may be a regionwith a shape which is possible to regulate so that it has anapproximately constant width.

The sub regions of the functional film are configured to a shape thatcan be regulated so that it has an approximately constant width,excelling in the precision of film thickness and the shape of thepattern.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingillustrations, wherein like numbers refer to like elements, and wherein:

FIG. 1 is an oblique illustration showing a schematic structure of adroplet discharge device in the embodiment;

FIG. 2 is a top view illustration, showing an example of gate wiringsfor Thin Film Transistors (TFTs);

FIG. 3 is a flow chart describing pattern-forming processes of the gatewirings;

FIG. 4A is an illustration showing a design pattern of the gate wiringfor the Thin Film Transistor (TFT), and FIG. 4B is an illustrationshowing a design pattern of dummy patterns;

FIG. 5 is an illustration showing an example of sub-regional division ofthe design pattern of the gate wiring;

FIG. 6 is a top view illustration showing a liquid substance patternformed in a first drawing process;

FIG. 7 is a top view illustration showing a liquid substance patternformed in a second drawing process;

FIG. 8 is a top view illustration showing a part of the dummy patternformed on a dummy substrate;

FIG. 9A and FIG. 9B are comparative examples to the embodiments, showingcommon examples of the liquid substance pattern;

FIG. 10 is an illustration showing the sub-regional division of thedesign pattern of the gate wiring in a first modified example;

FIG. 11 is an illustration showing the sub-regional division of thedesign pattern of the gate wiring in a second modified example;

FIG. 12 is an illustration showing the sub-regional division of thedesign pattern of the gate wiring in a third modified example;

FIG. 13 is an illustration showing the sub-regional division of thedesign pattern of an electrode wiring in a forth modified example; and

FIG. 14 is a top view illustration showing the liquid substance patternformed in the second drawing process in a fifth modified example.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

The desirable embodiments of the present invention will now be describedin detail using the attached illustrations.

The embodiments described hereafter are the specific examples desirableto the invention, in which various technical limitations appropriate tothose examples are appended. However, the scope of the present inventionshall not be limited to those configurations, unless there is a specificstatement to limit the invention in the descriptions hereafter. The sizeratio of the patterns shown in the figures referred in the descriptionshereafter does not necessarily match the real size ratio.

(Structure of Droplet Discharge Device)

First, a structure of a droplet discharge device used for drawingpatterns is described with reference to FIG. 1. FIG. 1 is an obliqueillustration showing a schematic structure of the droplet dischargedevice in the embodiment.

A droplet discharge device 100, as shown in FIG. 1, includes: a headmechanism 102, which has a head unit 110 that discharges droplets; asubstrate mechanism 103 which is formed on a substrate 120, which is adroplet discharge target of droplets discharged from the head unit 110;a liquid substance supply unit 104 that supplies a liquid substance 133to the head unit 110; and a control unit 105 that controls the supplyunit and each of the mechanisms as a whole.

The head unit 110 has a plurality of nozzles, and can discharge dropletsfrom each nozzle toward the substrate 120. The discharge of the dropletscan be controlled per nozzle by the control unit 105. Most flatplate-like materials, such as a glass substrate, a metal substrate, asynthetic resin substrate or the like, can be utilized as the substrate120.

The droplet discharge device 100 is provided with a plurality ofsupporting legs 106 placed on the floor, and a surface plate 107 placedon them. On the upside of the surface plate 107, the substrate mechanism103 is arranged in the lengthwise direction (direction of X-axis) of thesurface plate 107, and above the substrate mechanism 103, the headmechanism 102, supported at its ends by two pillars that are fixed onthe surface plate 107, is arranged in the direction that crosses thesubstrate mechanism 103 at a right angle (direction of Y-axis).Moreover, on one of the edge of the surface plate 107, the liquidsubstance supply unit 104, which is connected from the head unit 110 ofthe head mechanism 102, supplies the liquid substance 133. Further, thecontrol unit 105 is placed, under the surface plate 107.

The head mechanism 102 is provided with: the head unit 110 thatdischarges the liquid substance 133; a carriage 111 that mounts the headunit 110; a Y-axis guide 113 that guides the carriage 111 to move in thedirection of Y-axis; a Y-axis drilling screw thread 115 arranged alongthe Y-axis guide 113; a Y-axis motor 114 that rotates the Y-axisdrilling screw thread 115 forward and backward; and a carriage screw-inportion 112, in which an internal thread portion that moves the carriage111 while screwing in with the Y-axis drilling screw thread 115, isformed, the carriage screw-in portion 112 being located under thecarriage 111.

The moving mechanism of the substrate mechanism 103 is arranged in thesimilar structure as that of the head mechanism 102, in the direction ofX-axis, and includes: a placement table 121 that holds the substrate120; an X-axis guide 123 that guides the placement table 121 to move; anX-axis drilling screw thread 125 arranged along the X-axis guide 123; anX-axis motor 124 that turns the X-axis drilling screw thread 125 forwardand backward; and a placement table screw-in portion 122, located underthe placement table 121, and moves the placement table 121 whilescrewing in with the X-axis drilling screw thread 125.

In the head mechanism 102 and in the substrate mechanism 103, alocation-detecting unit (not shown), which detects the location of thehead unit 110 and the placement table 121 after their movement, isprovided respectively. There is a mechanism, which adjusts the directionof rotation, the direction thereof being the Z-axis that is orthogonalto the X-axis and the Y-axis, is embedded into the carriage 111 and theplacement table 121, and allows the adjustment of rotation direction ofthe head unit 110 and of the placement table 121.

With such structure, the head unit 110 and the substrate 120 canreciprocate freely relatively to the Y-axis and the X-axis. Thedescription of the head unit 110 is as follows. The Y-axis drillingscrew thread 115 rotates forward and backward by bi-directional rotationof the Y-axis motor 114. The carriage 111, which is unified with thecarriage screw-in portion 112, moves to a given location, as thecarriage screw-in portion 112, which is screwed together to the Y-axisdrilling screw thread 115, moves along the Y-axis guide 113. In otherwords, the drive of the Y-axis motor 114 allows a free movement of thehead unit 110 mounted on the carriage 111, in the direction of Y-axis.Similarly, the substrate 120 placed on the placement table 121 movesfreely in the direction of X-axis.

As described, with the drive control of the X-axis motor 124 and theY-axis motor 114, a relative move of the head unit 110 to the substrate120 is enabled, so that the droplets can be discharged to a givenlocation on the substrate 120. Moreover, synchronization of the locationcontrol and the discharge control of the head unit 110 allows a drawingof a given pattern on the substrate 120.

The liquid substance supply unit 104, which is located at one end of thesurface plate 107, supplying the liquid substance 133 to the head unit110 includes: a tube 131 a that forms a channel that connects to thehead unit 110; a pump 132 that sends in the liquid to the tube 131 a; atube 131 b (channel) that supplies the liquid substance 133 to the pump132; and a tank 130, connected to the tube 131 b and stores the liquidsubstance 133.

(About Forming Gate Wiring)

Hereafter, the pattern formation of the functional film is describedusing a gate wiring for Thin Film Transistor (TFT) as an example. Notethat this gate wiring in the explanation below is merely an example ofthe functional films, and the functional film, to which the presentinvention applies, varies widely. The variation includes: an widevariety of variations of patterns of conductive film (wiring) in anelectronic device; a luminescence cell film of an organic electroluminescence (EL) display panel; and a color filter film of a liquidcrystal display panel, etc.

(Structure of Gate Wiring)

FIG. 2 is a top view illustration, showing an example of gate wiringsfor TFTs.

In FIG. 2, a gate wiring 34 corresponds to the functional film accordingto the embodiment of the invention. Each of the plurality of gatewirings 34 formed in strip has a wide portion 34A, a gate electrodeportion 34B and a narrow portion 34C. Here, in FIG. 2, ratio of lengthsand widths of the wide portion 34A, the gate electrode 34B, and thenarrow portion 34C does not necessarily match the actual ones.

The wide portion 34A is a main part that extends itself in the directionof X-axis in the gate wiring 34. Moreover, the width of the wide portion34A, in other words, the length of the side that is orthogonal to thelengthwise direction of the wide portion 34A, is longer than the widthsof the gate electrode portion 34B and the narrow portion 34C. Morespecifically, the width of the wide portion 34A is approximately 20 μm.

The gate electrode portion 34B sticks out from the wide portion 34A inthe direction of Y-axis, and constitutes a gate electrode of a TFTelement. The width of the gate electrode portion 34B is approximately 10μm, which is shorter than the width of the wide portion of 34A.

The width of the narrow portion 34C is narrower than the wide portion34A in the gate wiring 34. This portion is at a location, where a sourcewiring and a drain wiring (neither of them shown), formed by a devicemanufacturing process (described later), cross. Hence, in order toreduce the electro capacitance generated by the overlap of wirings, thewidth of the narrow portion 34C is formed narrow. More specifically, thewidth of the narrow portion 34C is approximately 7 μm.

(Schematic Structure of Liquid Substance)

The liquid substance for forming the gate wiring 34 may include asubstance in which conductive microparticles, which serves as afunctional material, are dispersed in disperse medium. Variations ofconductive microparticles dispersed in the liquid substance may include:metallic microparticles containing any one of gold, silver, copper,palladium, or nickel; conductive polymer or superconductingmicroparticle, etc.

These conductive microparticles can have organic matter or the like,coated on their surfaces, in order to improve the dispesibility.Examples for the coating material for coating the surfaces of themicroparticles could be citric acid, etc.

The particle size of the conductive microparticle is preferably between5 nm and 0.1 μm inclusive. This is because, if the size is larger than0.1 μm, nozzle clogging of the head of the droplet discharge device(described later) tends to occur, and the discharge with dropletdischarge method becomes troublesome. Further, if the size is smallerthan 5 nm, a volume ratio of the coating material to the conductivemicroparticle increases, and the proportion of the organic matterobtained in the film becomes excessive.

The room temperature vapor pressure of the disperse medium of the liquidthat contains the conductive microparticles is preferably between 0.001mmHg and 200 mmHg inclusive (approximately equal to or larger than 0.133Pa and 26600 Pa or less). This is because if the vapor pressure ishigher than 200 mmHg, the disperse medium rapidly evaporates after thedischarge, and the formation of favorable film becomes difficult.

The vapor pressure of the disperse medium is preferably between 0.001mmHg and 50 mmHg inclusive (approximately equal to or larger than 0.133Pa and 6650 Pa or less). This is because if the vapor pressure is higherthan 50 mmHg, nozzle blockage caused by the desiccation tends to occur,when discharging droplets with the droplet discharge method, and thesafe discharge becomes difficult.

On the other hand, if the vapor pressure of the disperse medium in theroom temperature is lower than 0.001 mmHg, the desiccation slows downand the disperse medium tends to stay in the film; hence it becomesharder to obtain a high quality conductive film after a thermal and/orphoto processing (post processing).

Which disperse medium to be used is not specifically limited as long asthe conductive microparticles can be dispersed and does not causeaggregation. More specifically, the material may include: water;alcohols such as methanol, ethanol, propanol, butanol, etc.; chemicalcompound of hydrocarbon halide system, such as n-heptane, n-octane,decane, toluene, xylene, cymene, durene, indene, dipentene,tetrahydronaphthalene, decahydronaphthalene, cyclohexylbenzene, etc.;chemical compound of ether system, such as ethylene glycol dimethylether, ethylene glycol diethyl ether, ethylene glycol ethyl methylether, diethylene glycol dimethyl ether, diethylene glycol diethylether, diethylene glycol methyl ethyl ether, 1,2-dimethoxyethane,bis(2-methoxyethyl) ether, p-dioxane, etc.; and polar compound such aspropylene carbonate, Υ-butyrolactone, N-methyl-2-pyrrolidone,dimethylformamide, dimethyl sulfoxide, cyclohexanone, etc. Among theabove, water, alcohols, chemical compound of hydrocarbon halide system,chemical compound of ether system are preferable in terms of easiness inapplying to the droplet discharge method, among which water and thechemical compound of hydrocarbon halide are more suitable. Thesedisperse mediums can be used by itself or as a mixed composite of 2 ormore variations.

Dispersoid density of the conductive microparticles should preferably bebetween 1 to 80 weight fraction inclusive, and can be adjustedcorresponding to the film thickness of the desired conductive film. Morethan 80 weight fraction tends to cause aggregation, and it becomes moredifficult to obtain an even film.

Surface tension of the liquid substance should preferably be in therange of 0.02 N/m and 0.07 N/m inclusive. When discharging the liquidsubstance with the droplet discharge method, if the surface tension isless than 0.02 N/m, the wetting of an ink composition against a surfaceof the nozzle increases; hence a flight course bending tends to occur.If the surface tension exceeds 0.07 N/m, then the meniscus formation atthe tip end part of the nozzle does not stabilize; causing the controlof the discharge quantity and the discharge timing to be difficult.

In order to adjust the surface tension, a small amount of surfacetension adjustment material can be added into disperse liquid, as longas it does not unreasonably decline a contact angle with a substrate S.The material may be of fluorine, silicon, non-ion systems. The surfacetension adjustment material of non-ion system betters the wetting of theliquid against the substrate, improves the leveling of the film, andcontributes to prevent the occurrence of asperity or orange peel surfaceof the film. The disperse liquid may contain organic chemical compoundsuch as alcohol, ether, ester, ketone or the like, if necessary.

Moreover, binder resin can be added into the liquid substance in orderto improve a fixative when it is formed into a film. Copolymer ofacrylates or styrene, for instance, may be used for the binder resin.Considering the fixative of the formed film, the larger the quantity ofthe binder resin the better. However, considering the conductivity,which is the main function of the conductive film, it is desirable thatthe quantity of the binder resin is small.

It is desirable that the viscosity of the disperse liquid is between 1mPa·s and 50 mPa·s inclusive. When discharging liquid with the dropletdischarge method, if the viscosity is smaller than 1 mPa·s, then theperipheral of the nozzle tends to be contaminated by the spill out ofthe ink; and if the viscosity is larger than 50 mPa·s, then the cloggingfrequency of the nozzle hole increases, toughening the smooth dropletdischarge.

(Overall Explanation of Gate Wiring Formation Process)

Hereafter, the overall process of the gate wiring formation will bedescribed using the flow chart in FIG. 3, and with reference to FIGS.4A, 4B and FIGS. 5 through 7. FIG. 3 is the flow chart describingpattern-forming processes of the gate wirings. FIG. 4A is anillustration showing a design pattern of the gate wiring. FIG. 4B is anillustration showing the design patterns of dummy patterns. Here, thedesign pattern means a motif pattern of the functional film to beformed, and is represented this way in order to distinguish itself fromthe actual pattern formed with the liquid substance or film material.

Prior to the pattern formation of the aforementioned gate wiring 34(refer to FIG. 2), a substrate is prepared (S1 a of FIG. 3). Materialsfor the substrate is appropriately selected from glass, silicon, resin,or the like, and applied according to the kind of device to manufacture,and which part of the device it is for. In the embodiments, the glasssubstrate is used. Here, another substrate with the same condition asthat of the one used for a product (in terms of quality of material,smoothness of surface, etc.), is also prepared as a dummy substrate (S1b of FIG. 3).

Thereafter, a liquid-repellent processing is performed on the substratesurface (plane on which the wiring pattern will be formed) (S2 a of FIG.3). The liquid-repellent processing may include, for instance, a methodof forming a self assembled monolayer on the substrate surface. “SAM:Self-Assembled-Monolayerse” is a fine single layer of molecules, inwhich a chemical compound coexists with a frame plane in either fluid orgas form, the chemical compound, in which a functional group that can bebonded with constituent atoms of the formation surface of the film isbonded in a linear chain molecule. Therefore the functional group isadsorptive to film forming surfaces, and is bonded with the constituentatoms on them. Thereby, the SAM is formed on the film-forming surface inthe linear chain molecule. In the embodiments, the SAM is formed byleaving the substrate andheptadecafluoro-tetrahydro-desyl-triethoxysilane, in a same airtightcontainer in the room temperature for 96 hours. Here, theliquid-repellent processing with the same condition is performed on thedummy substrate prepared previously (S2 b in FIG. 3).

After the liquid-repellent processing (S2 a of FIG. 3), a hydrophilicprocessing is performed on a region for forming the gate wiring, on thesubstrate surface (S3 a of FIG. 3). More specifically, the hydrophilicprocessing is conducted with: plasma oxygen being radiated via a mask(plasma processing method), which is die-cut with the design pattern ofthe gate wiring (refer to FIG. 4A); and a removal of self-assembledmolecules and other adhered impurities in the irradiated region.

With this process, the hydrophilic region in the design pattern of thegate wiring is formed on the substrate surface. Since the outside ofthis hydrophilic region is liquid-repellent region, it is possible, inthe pattern forming process described later, to form the liquidsubstance pattern in accordance with the design pattern, in a highprecision.

Here, the similar hydrophilic processing is performed on the dummysubstrate prepared in advance (S3 b of FIG. 3). However, unlike the caseof the proper substrate, the hydrophilic region formed has a long andthin strap-like shape as shown in FIG. 4B.

The aforementioned liquid-repellent processing process and thehydrophilic processing process are together called a pre-substrateprocessing process. This pre-substrate processing process is conductedin order to form a liquid substance pattern in a high precision, inaccordance with a design pattern 30. Note that the pre-substrateprocessing process is not a mandatory process for conducting the patternforming process that will be described later, and is not mandatory inorder to obtain the effect of the invention.

In addition to the aforementioned method, the pre-processing process ofthe substrate may include a method so called a bank formation, whichwill now be described.

In the bank formation, a bank-shaped resin structure (a bank) is formedon the substrate along the outline of the design pattern by using aresist technique. An arylic resin used here may include a polyimideresin, or the like.

The hydrophilic process may be performed on the substrate surface priorto the bank formation, and the liquid-repellent processing may beconducted to the bank portion after the bank formation. The plasmaprocessing method (CF4 plasma processing method), with the use oftetrafluoromethane as a processing gas in atmospheric air, may, forexample, be used as the liquid-repellent processing method. Theliquid-repellent processing may be omitted by using, as the bank resin,the material with water-repellency (a resin material with fluorinegroup, for instance).

After the hydrophilic processing processes (S3 a, S3 b), the liquidsubstance discharge is conducted on the dummy substrate, so as to draw adesign pattern 31 shown in FIG. 4B; thereby the dummy pattern is formed(S4 in FIG. 3). Here, the quantity of the liquid substance arranged onthe dummy substrate is equal to the amount necessary in order to obtaina film thickness of a production-ready gate wiring 34 (refer to FIG. 2).

In FIG. 4B, the design pattern 31 of the dummy pattern consists ofstrap-like portions 31A, 31B, and 31C with long and thin strap-likeshapes, and the width of the strap-like portion 31A is equal to that ofa wide portion 30A, which corresponds to the wide portion 34A in FIG. 2,in the design pattern 30 of the gate wiring. Moreover, the width of thestrap-like portion 31B and the width of the strap-like portion 31C arerespectively equal to those of the a gate electrode portion 30B(corresponding to the gate electrode portion 34B in FIG. 2), and anarrow portion 30C (corresponding to the narrow portion 34C in FIG. 2),both of which are in the design pattern 30 of the gate wiring.

The dummy pattern forming process deeply relates to a subsequent subregion configuration process (S5 in FIG. 3), which will be described indetail later.

After the dummy pattern forming process, the design pattern 30 of thegate wiring (shown in FIG. 4A) is divided into sub regions, each ofwhich is categorized into groups (sub region configuration process S5 inFIG. 3). This sub region configuration process does not include anyprocessing to the substrate, and rather, it is a kind of an informationprocessing.

FIG. 5 is an illustration showing an example of sub-regional division ofthe design pattern of the gate wiring. In this figure, borders betweenthe adjacent sub regions are shown in imaginary lines. Further, out ofconvenience, sub regions that belong to the same group are shown in thesame hatching.

As shown in FIG. 5, the design pattern 30 is divided into rectangularshaped sub regions 40 a through 40 g. The wide portion 30A consists ofthe sub regions 40 b and 40 d (40 a) with 20 μm in width and 35 μm inlength, and the sub region 40 c with 20 μm in width and 30 μm in length.The region in the gate electrode portion 30B is the sub region 40 g with10 μm in width and LB1 in length. The region in the narrow portion 30Cis the sub region 40 e (40 f) with 7 μm in width and LC1 in length.

The grouping of the sub regions are performed in a way that any adjacentsub regions do not belong to the same group. In the embodiments, asshown in FIG. 5, the sub regions 40 a, 40 b, and 40 d are categorized inA group, and the sub regions 40 c, 40 e, 40 f and 40 g are categorizedin B group. Particularly, in the embodiment, the sub region 40 g,regulated to have the width of the gate electrode portion 30B (10 μm),and the sub regions 40 e and 40 f, regulated to have the width of thenarrow portion 30C (7 μm), all belongs to the same B group. Therefore,in the case of configuring sub regions so that sub regions that areregulated to have comparable widths belong to the same group, morepertinent control can be expected (described in detail later). Thegrouping does not necessarily result in 2 groups. As long as itsatisfies the condition of “adjacent sub regions not belonging to thesame group”, it can result in 3 or 4 groups.

As described, the design pattern 30 consisting of complex shapes, isdivided into the rectangular sub regions 40 a through 40 g regulated sothat they have a given width and length, and those sub regions aresorted into groups. There are several points of concern for sub-regionaldivision, which deeply relates to the aforementioned dummy patternforming process (S4 of FIG. 3), and which will be described in detaillater.

When the sub-regional division and the grouping is performed, the liquidsubstance discharge is conducted based on the design pattern 30 afterthe sub region configuration (refer to FIG. 5) (A first drawing processS6 in FIG. 3). More specifically, the design pattern 30 shown in FIG. 5is stored in the droplet discharge device 100, then the substrate, onwhich the pre-substrate processing (S2 a and S3 a in FIG. 3) isperformed, is placed on the placement table 121 (refer to FIG. 1), andthe drawing with the droplet discharge method is conducted.

FIG. 6 is a top view illustration showing a liquid substance patternformed in a first drawing process. In the figure, regions shown invirtual lines indicate the design pattern (sub regions) shown in FIG. 5.

As shown in FIG. 6, in the first drawing process, the liquid substancedischarge is conducted so as to draw the sub regions 40 a, 40 b and 40 d(refer to FIG. 5) that belongs to the A group in the design pattern 30,and patterns of liquid substance 33 a, 33 b and 33 d (shown in hatching)are formed. On the substrate surface, the hydrophilic/liquid-repellentprocessing has already been performed in accordance with the designpattern 30 of the gate wiring shown in FIG. 4A, allowing the formationof patterns with sharp outlines.

Since the sub regions 40 a, 40 b and 40 d that belong to the A group areselected so as not be adjacent to each other, the patterns of liquidsubstance 33 a, 33 b, and 33 d each take an individual pattern. In otherwords, these patterns are governed by individual kinetic systems, whichalso means that the pattern control is conducted by the unit of subregions 40 a, 40 b, and 40 d.

Thereafter, the patterns of liquid substance 33 a, 33 b, and 33 d aredried, and the functional material etc., contained in the liquidsubstance, is fixed on the substrate (a first drying process S7 in FIG.3). The drying process as a solidification process may be conduced withthe substrate transferred to a drying device, or it may also beconducted with the substrate placed on the placement table 121 (refer toFIG. 1) by a manufacturing device that combines the droplet dischargedevice 100 (refer to FIG. 1) and the drying device. In this dryingprocess, the disperse medium and other kinds of solvents evaporate, andwiring films 38 a, 38 b, and 38 d are formed as the conductive filmscontaining conductive material.

Thereafter, the liquid substance discharge is conducted again (a seconddrawing process S8 in FIG. 3) to the substrate, on which the firstdrying process forms the wiring films 38 a, 38 b, and 38 d. Morespecifically, the liquid substance is discharged so as to draw the subregions 40 a, 40 b, and 40 d that belong to the B group, and thepatterns of liquid substance are formed.

FIG. 7 is a top view illustration showing the liquid substance patternformed in the second drawing process.

In FIG. 7, patterns of liquid substance 33 c, 33 e, 33 f and 33 g (shownin hatching) are formed as the patterns that correspond to the subregions 40 c, 40 e, 40 f, and 40 g in FIG. 6. On the substrate surface,the hydrophilic/liquid-repellent processing has already been performedin accordance with the design pattern 30 of the gate wiring shown inFIG. 4A, allowing the formation of patterns with sharp outlines.

Since the sub regions 40 c, 40 e, 40 f, and 40 g that belong to the Bgroup are selected so as not be adjacent to each other, the patterns ofliquid substance 33 c, 33 e, 33 f, and 33 g that correspond to thisgroup region, each take an individual pattern. That is to say, thesepatterns are governed by individual kinetic systems. Moreover, in otherwords, it also means that the pattern control is conducted by the unitof sub regions 40 c, 40 e, 40 f, and 40 g.

After forming the patterns of liquid substance 33 c, 33 e, 33 f, and 33g, the whole substrate is dried by, for instance, transferring it to thedrying device (a second drying process S9 in FIG. 3), and the functionalmaterial etc., contained in the liquid substance is fixed on thesubstrate. The patterns of liquid substance 33 c, 33 e, 33 f, and 33 gare united with the previously formed wiring films 38 a, 38 b, and 38 d;thereby forming the gate wiring 34 (refer to FIG. 2).

The substrate, on which the gate wiring 34 (refer to FIG. 2) is formed,undergoes firing if required; thereafter it is transferred into thedevice manufacturing process; and then it is utilized as a wiring etc.,of, for instance, the display device.

As described in the above explanation, the design pattern is dividedinto the plurality of sub regions; and drawing and drying of thepatterns per non adjacent group of sub regions are conducted; therebyallowing the reliable control of the patterns of liquid substance inunits of sub region.

(Details of Pattern Preparation Process)

In the above process, the dummy pattern forming process (S4 in FIG. 3)and the sub region configuration process (S5 in FIG. 3) are togethercalled a pattern preparation process. Hereafter, the details of theseprocesses will be described with reference to FIGS. 8 and 9.

FIG. 8 is a top view illustration showing a part of the dummy patternformed on the dummy substrate, of which pattern corresponds to thestrap-like portion 31A in FIG. 4B.

In FIG. 8, the dummy pattern 32A made from the liquid substance does notmatch the strap-like portion 31A of the design pattern shown with thevirtual lines, and have bulges 36 (protruding portions), which areliquid huddling that occur at even intervals. As described, even if theliquid substance (droplet) accurately landed on the substrate accordingto the design pattern (strap-like portion 31A), the liquid substance onthe substrate behaves as governed by the kinetic effects such as wettingor surface tension, resulting in cases of its shape changing orsplitting. One example of such cases is the occurrence of the bulges 36that emerge when drawing, with the liquid substance, the design patternthat is extended long and thin. According to the knowledge of theinventor, the bulges 36 are thought to emerge as a result of the liquidsubstance arranged in a region with a narrow width, which causes theliquid substance to reduce the increased internal pressure.

Similar to the dummy pattern 32A in FIG. 8, the bulges 36 occur inapproximately even intervals in the dummy patterns that correspond tothe strap-like portion 31B and 31C shown in FIG. 4B, where the detailedexplanation thereof is omitted. The occurrence interval of bulges tendsto become shorter, as the width of the pattern narrows.

If bulges emerge when forming the liquid substance pattern as in thedummy pattern 32A in FIG. 8, the wiring film cannot be formed accordingto the design pattern. Therefore, it is important to know in advance thecondition in which the bulges emerge. However, the condition of bulgeimmersion changes, depending on: the hydrophilicity of the hydrophilicregion, the water-repellency of the liquid-repellent region; the surfacetension of the liquid substance; the width of the strap-like portion;and the amount of arranged liquid substance. Hence, it is difficult toascertain the condition applicable to various patterns by calculations.

This dummy pattern forming process is provided in consideration of theaforementioned circumstances. That is to say, by forming the dummypattern with the regions, which are extended long and thin, and areincluded in the design pattern 30 of the gate wiring (refer to FIG. 4A);in other words, with the strap-like patterns provided with the samewidths as that of the wide portion 30A, the gate electrode portion 30B,and the narrow portion 30C; it is possible to learn the relationshipsbetween the patterns and the widths.

For instance, in the example of the dummy pattern 32A shown in FIG. 8,the occurrence interval of the bulges 36 is approximately 90 μm. Due tothe above, if the liquid substance pattern is formed at once accordingto the design pattern 30 in FIG. 4A, there is a high possibility thatthe bulge will emerge in the region equivalent to the wide portion 30Athat extends in the length of 100 μm. In the embodiments, as shown inFIG. 5, the wide portion 30A is divided into the rectangular sub regions40 a, 40 b and 40 d, with 20 μm in width and 70 μm in length, as well asinto the sub regions 40 c, 40 e, 40 f and 40 g, with 20 μm in width and45 μm in length. As described, by dividing the wide portion 30A into thesub regions, of lengths equal to or smaller than the occurrence interval(approximately 90 μm) of the bulges 36 in the dummy pattern 32A, theimmersion of the bulges can be preemptively prevented in the case offorming the liquid substance pattern.

The similar issue applies to regions equivalent to the gate electrodeportion 30B or the narrow portion 30C. However, in the case of theembodiments, the lengths of the sub regions 40 e and 40 f are shorterthan the occurrence intervals of the bulges that emerge in the dummypattern corresponding to the strap-like portions 31B and 31C (refer toFIG. 4B); hence there is no need to divide the region.

The occurrence of the aforementioned bulges is an example of the casesthat the liquid substance pattern changes its shape due to the kineticeffects such as wetting or surface tension. Yet, moreover, there isanother typical example other than such case, which will be describedwith reference to FIGS. 9A and 9B. FIG. 9A and FIG. 9B are comparativeexamples to the embodiments, sectional illustrations showing commonexamples of the liquid substance pattern.

A liquid substance pattern 90, shown in FIGS. 9A and 9B, is a schematicillustration equivalent to an imaginary line region E in FIG. 4A. InFIG. 9A, the thickness of a narrow portion 90C (corresponding to thenarrow portion 30C in FIG. 4A) is thinner than that of a wide portion90A (corresponding to the wide portion 30A in FIG. 4A). Moreover, inFIG. 9B, the liquid substance pattern is not formed at the narrowportion 90C, taking a shape that the pattern 90 is disrupted in themiddle.

As described, in the location where the two regions with differentwidths come into conjunction, the transition of the liquid substanceoccurs between the two regions (in the example in FIGS. 9A and 9B, thewide portion 90A and the narrow portion 90C), which may result indefects or the immersion of inequality of film thicknesses. According tothe knowledge of the inventor, it is considered that such migrationphenomenon of the liquid substance is caused by the curvature differenceof the surface of the liquid substance between the wide portion 90A andthe narrow portion 90C. More specifically, if the pattern 90 isstructured in an approximately even thickness, then the surface of theliquid substance of the narrow portion 90C has larger curvature thanthat of the wide portion 90A. The difference occurs not only in thecurvature, but also in an internal pressure of the liquid substance, inorder to balance its surface tension; therefore, the migration of theliquid substance occurs due to the internal pressure difference,resulting in the pattern shown in FIG. 9A or 9B in its normal status.

In the embodiments, as shown in FIG. 5, the design pattern 30 of thegate wiring is divided into the sub regions regulated to have a constantwidth, such as: the sub regions 40 a through 40 d regulated to have thewidth of the wide portion 30A (20 μm); the sub region 40 g regulated tohave the width of the gate electrode portion 30B (10 μm); and the subregions 40 e and 40 f regulated to have the width of the narrow portion30C (7 μm). Within the sub regions that can be regulated so that theyhave a constant width such as rectangular shape, the liquid substancedoes not emerge the aforementioned migration, and can maintain shapestability; thereby allowing the formation of an even film.

As described above, in the case of forming the liquid substance pattern,the shape and the size of its design pattern have a great effect on thebehavior of the discharged liquid substance. With the pattern formingprocess according to the embodiments of the invention, the behavior ofthe liquid substance can be controlled by sub regional unit, regardlessof the shape and size of the design pattern; thereby allowing theformation of patterns in a high precision of line width and of shape,etc.

In the embodiments, the drawing and drying of the A group is precedingthat of the B group. Subsequently, the drawing and drying of the B groupis conducted and the gate wiring is formed. However, these processes canbe reversed. Here, it is desirable to select which preceding group ofdrawing and drying is to be conducted, by the degree of the wetting onthe hydrophilic region of the liquid substance, where the hydrophilicprocessing is performed in accordance with the design pattern 30 (referto FIG. 4A and FIG. 5).

In the case where the wetting is eminently large for instance, theliquid substance for the liquid substance patterns 33 a and 33 b spreadsto the narrow sub regions 40 e and 40 g, if the drawing of the A groupis conducted prior to the other; therefore resulting in a case where theprecise liquid substance pattern formation is difficult in the firstdrawing process. In such case, it is desirable to first conduct thedrawing and the drying of the B group that includes the narrow subregions. If the sub region configuration is conducted so that the subregions that are regulated to have similar widths belong to the samegroup, as in the embodiments, the control of regions by the order ofgroup unit becomes possible.

FIRST MODIFIED EXAMPLE

FIG. 10 is an illustration showing the sub-regional division of thedesign pattern of the gate wiring in a first modified example.Hereafter, descriptions of the parts overlapping the previous embodimentare omitted, and differences of the first modified example from theprevious embodiment will mainly be described.

As shown in FIG. 10, sub regions 41 a, 41 b, and 41 c that belong to thesub regions of the A group, and sub regions 41 d, 41 e, and 41 f thatbelong to the sub regions of the B group, are configured in the firstmodified example. Here, the sub region 41 f is a sub region regulated sothat it has the width of the gate electrode 30B (10 μm), which isconfigured to extend from the gate electrode portion 30B to the part ofthe wide portion 30A. The sub regions 41 b and 41 c (41 a) thatstructures the wide portion 30A are the sub regions with differentlength. Particularly, the sub region 41 b is a 20 μm×20 μm quadrate subregion.

As shown in this first modified example, it is not necessary that theregion have to be divided into the sub regions at the location where thewide portion 30A and the gate electrode portion 30B border on. What isimportant is to divide the region into “constant, possible-to-regulateshaped” sub regions; hence their shape can vary.

Moreover, the wide portion 30A does not have to be divided evenly. Whatis important is to divide the region into sub regions “with the lengthin which the bulges do not occur”, or “the length shorter than theoccurrence intervals of the bulges in the dummy pattern”; hence theirshape can vary.

Moreover, the quadrate sub region 41 b does not have a differentiationof which side is the width and which side is the length. However, evenif the liquid substance pattern is formed in quadrates, it is obviousthat the pattern can maintain shape stability. Thus, there is no logicalreason as to determine that the quadrate is not a “shape having anapproximately constant width”. That is to say, the “shape having anapproximately constant width” according to the embodiments of theinvention should also be determined in view of whether or not thepattern can maintain stability when the pattern is formed with suchshapes. Quadrates naturally fall under that category.

SECOND MODIFIED EXAMPLE

FIG. 11 is an illustration showing the sub-regional division of thedesign pattern of the gate wiring in a second modified example.Hereafter, descriptions of the parts overlapping the previousembodiments are omitted, and differences of the second modified examplefrom the previous embodiment will mainly be described.

As shown in FIG. 11, sub regions 42 a, 42 b, and 42 c that belong to thesub regions of the A group, sub region 42 f that belong to the B group,and sub regions 42 d, 42 e, and 42 g that belong to the sub regions ofthe C group, are configured in the second modified example.

As mentioned in the second modified example, the number of groups, intowhich the sub regions are categorized, can be three. In this case,drawing and drying are conducted first on the A group, thereafter on theB group, and finally on the C group. In other words, it does not matterhow many groups there will be, yet, the larger the number of groups, thelonger the time it takes for the entire process.

Here, in the second modified example, the sub regions 42 f and 42 g,which are regulated so that they have the width of the gate electrode30B (10 μm), are configured in a way that they are divided, in theY-axis direction, from the sub region 41 f in the first modifiedexample. As described, the sub regional configuration does not deny thesegmentalized division.

THIRD MODIFIED EXAMPLE

FIG. 12 is an illustration showing the sub-regional division of thedesign pattern of the gate wiring in a third modified example.Hereafter, descriptions of the parts overlapping the previousembodiments are omitted, and differences of the third modified examplefrom the previous embodiment will mainly be described.

As shown in FIG. 12, sub regions 43 a, 43 b, and 43 e that belong to theA group, and sub regions 43 c, 43 d, and 43 f that belong to the Bgroup, are configured in the third modified example. Here, the subregions 43 b and 43 c have a slight step or curvy outline, which cannotbe strictly called a rectangular sub region.

The sub regions 43 d and 43 e regulated to have the width of the narrowportion 30C (7 μm), can belong to different groups, as in the thirdmodified example. Moreover, the shapes of the sub regions 43 b and 43 c,which cannot be strictly called rectangular, are also included in a“shape having an approximately constant width” according to theembodiments of the invention, as long as they can be objectivelyregulated so that it has a constant width (in this case, 20 μm).

FORTH MODIFIED EXAMPLE

FIG. 13 is an illustration showing the sub-regional division of thedesign pattern of the gate wiring in a forth modified example.Hereafter, descriptions of the parts overlapping the previousembodiments are omitted, and differences of the forth modified examplefrom the previous embodiments will be mainly described.

As shown in FIG. 13, a design pattern 60 includes a circular sub region61 a, a bended belt-shaped sub region 61 c, and a trapezoid sub region61 e, as the A group. Moreover, it includes an approximately rectangularsub region 61 b and a trapezoid sub region 61 d as the B group.

The circular sub region 61 a, when its diameter is considered as awidth, can be presumed to be regulated so that it has a constant widthin the rotation direction with is center as a rotation axis. Moreover,similar to the case of quadrates, even the liquid substance pattern isformed in a circular shape, it is obvious that the pattern can maintainthe shape stability. Therefore, the “constant, possible-to-regulateshape” means a shape that can be regulated so that it has a constantwidth (diameter) in a translation or in one rotation direction, and thecircular shapes fall under the category of the “shape having anapproximately constant width” according to the embodiments of theinvention. Further, the bended belt-shape such as the sub region 61 c,or trapezoid of which the length difference of the upper base and thelower base is small, such as the sub regions 61 d and 61 e, also fallunder the category of the “shape having an approximately constant width”according to the embodiments of the invention.

FIFTH MODIFIED EXAMPLE

FIG. 14 is a top view illustration showing the liquid substance patternformed in the second drawing process in a fifth modified example.Hereafter, descriptions of the parts overlapping the previousembodiments are omitted, and differences of the fifth modified examplefrom the previous embodiment will mainly be described.

In the fifth modified example, sub regions 40 c, 40 e, 40 f, and 40 gthat belong to the B group (refer to FIGS. 5 and 6) are not drawn, inthe second drawing process, in their target size. Rather, the patternsare formed so that some parts of those sub regions overlap with thepre-formed wiring films 38 a, 38 b, and 38 d. In other words, the liquidsubstance patterns 37 e, 37 f, and 37 g have the same width as thecorresponding sub regions 40 e, 40 f, and 40 f (FIGS. 5 and 6), and areformed slightly longer in the direction of their long sides.

As described in the fifth modified example, the liquid substance patterndoes not necessarily need to be formed strictly according to theconfigured sub regions, and it can also be formed so that parts of subregions overlap with those of another group.

The invention shall not be limited to the above-mentioned embodiments.That is to say, for instance, when the design pattern is constructedwith regions that have various widths, those regions do not necessarilybe divided, as long as the shape and film thickness distribution arestable within those ranges. Moreover, each structure of each embodimentmay be appropriately combined with each other, omitted, or combined withother structures (not shown).

1. A pattern forming method for forming a luminescent film with apredetermined pattern on a substrate using a droplet discharge method todischarge a plurality of droplets of a liquid material, the patternforming method comprising: a step of dividing the predetermined patternof the film into a plurality of sub regions, said step includingcategorizing the plurality of sub regions into at least a first groupand a second group, adjacent sub regions being categorized intodifferent groups; a first drawing step of discharging the liquidmaterial so as to draw at least one sub region that belongs to the firstgroup; and a second drawing step of discharging the liquid material soas to draw at least one sub region that belongs to the second group;wherein the liquid material discharged in the first drawing step issolidified before the second drawing step.
 2. The pattern forming methodaccording to claim 1, wherein the sub regions categorized into the firstgroup each have a width that is approximately equal, and the sub regionscategorized into the second group each have a width that isapproximately equal, the widths of the sub regions in the first groupbeing different than the widths of the sub regions in the second group.3. The pattern forming method according to claim 2, wherein sub regionshaving comparable widths are categorized to the same group.
 4. Thepattern forming method according to claim 1, wherein: the design patternof the luminescent film includes an extended region that extendsrelative to the sub regions; the sub regions are configured along adirection in which the extended region extends to segment the extendedregion at a certain prescribed length; and the prescribed length isequal to one interval between protruding portions which emerge inapproximately even intervals in the predetermined pattern, formed if asecond liquid material is discharged to draw a stripe-shaped patternwith the same width as the extended region.
 5. The pattern formingmethod according to claim 4, further comprising: a step of forming adummy pattern , which is performed prior to the step of configuring thesub regions, by arranging the second liquid material on a dummysubstrate to draw the stripe-shaped pattern with the same width as theextended region; wherein the prescribed length is regulated by intervalsbetween the protruding portions which emerge in approximately evenintervals in the dummy pattern.
 6. The pattern forming method accordingto claim 1, wherein a surface of the substrate is subjectedliquid-repellent processing or a bank is formed on the surface of thesubstrate in a manner that surrounds a region corresponding to thedesign pattern of the luminescent film.